What is a good book on a real insider's view of D.C. politics esp Senate?

I am looking for a real good book on the true politics of Washington D.C. especially the Senate. It appears despite being public opposites according to some books I have read (including even the Audacity of Hope by Barack Obama) they all share cigars and go to the same places. To me it seems like a exclusive club, and the Republican/Democratic thing is a front depending on what it takes to get them re-elected. Is there any good book that depicts this truth?